The bones were found only after bushes covering them were razed by a wildfire.

The governor said the bones were discovered two days ago about 300 metres from the Ban Phue-Kut Chap Road by reporters from Channel 9 who were in the area working on two other crime stories.

Mr Chayawut said provincial police had launched an investigation into the grisly find, speculating that a number Udon Thani officials could be involved.

"I would like to assure the people of Udon Thani that I, the regional police chief, and commander of the 24th Army Circle will closely work together to bring the culprits in this case to justice," the governor wrote.

Police and soldiers will comb through a forest in Ban Phue district as they widen their investigation into possible gangland killings involving police guns-for-hire.

The thorough search of a Ban Khambon Wiangchai forest in tambon Nong Waeng of Ban Phue district will start on Sunday, Pol Maj Gen Khajonsak Pansakhon, deputy commissioner of the Provincial Police Region 4, said on Friday.

"We have requested equipment such as metal detectors from the military and border patrol police to collect all the evidence we can, including bullet slugs and spent cartridges, at 16 locations. The search will involve soldiers and police walking through the forest in line abreast," he said.

A combined force of police officers and soldiers combing an area where burnt human bones were found last week in Ban Phue district discovered more burnt bones at five other spots on Sunday, police said.

Police last week searched the area located about 400 metres off a gravel road to Ban Khambon Wiang Chai in tambon Nong Waeng and discovered 16 piles of burnt human bones, apparently after the bushes were razed in a recent wildfire.

A new search was carried out on Sunday involving 50 army officers from Prajak Silpakhom Military Camp and 50 local police including provincial forensic science officers. Scanners were also used to detect bullets and spent cartridges.

More burnt bones were found at five other spots, bringing the number of spots with piles of burnt human bones to 21.

The newly-found bones would be sent to the Forensic Medicine Institute at the Police Hospital in Bangkok for examination on Monday.

The result was expected to be known in two weeks, said Pol Maj Gen Peerapong Wongsaman, the Udon Thani police chief.

It was reported that residents in nearby areas suspected the site was where victims were brought to be killed and burnt, mostly sitting on auto tyres. Some of the victims were said to have been burnt alive.

Human skeletons among piles of skeletons collected from forest in Udon Thani

The Institute of Forensic Medicine has now confirmed that human skeletons were among piles of skeletons collected from more than 20 locations within the degraded forest areas of Ban Pheu district of Udon Thani province.

Head of the Royal Thai Police’s Forensic Medicine Pol Maj Dr Pornchai Suthirakun disclosed today that DNA tests on skeletons collected from 20 places at the forest areas of Ban Kambon Viengchai in Tambon Nongwaeng of Ban Pheu district initially proved human skeletons were among these skeletons.

He said as there are large piles of skeletons to be tested and many had been burnt and extremely dried, it needed more time to differentiate all of them from animal bones.

But since human skeletons are among these bones, he has asked the forensic police to send DNA samples from those who earlier reported their relatives went missing for laboratory test if they match the skeletons found, he said.

THE DNA test results of human remains found at one of 23 spots in the degraded forest of Udon Thani’s Ban Phue district have been released and are pending comparison with the 31 relatives of missing persons, deputy police spokesman Pol Colonel Krissana Pattanacharoen said yesterday.The move followed the discovery in April of skeletons - many with signs of burning - in the forest located between Pa Som, Sangkhom and Ban Phue. It is suspected that these people were burned on piles of rubber tyres in an attempt to cover up the murders.

Citing confirmation from Pol Maj-General Pornchai Sutheerakun, chief of the Institute of Forensic Medicine, that the DNA test results have been completed, Krissana however declined to elaborate on details such as the sex of the victims. He said it would be dependent on comparison with 31 relatives who have come forward with reports of missing persons.

Should the DNA samples match, police will go ahead with issuing summonses and arrest warrants, he said, adding that forensic tests in other spots should be completed by this month's end.

Krissana affirmed that Provincial Police Region 4 and Udon Thani police investigators were working on hunting down the suspects linked to this site, but he could not reveal who the police had talked to, as it could affect the ongoing investigation.

Justice Minister Paiboon Koomchaya said the case was the Royal Thai Police's responsibility and nobody had asked for the Department of Special Investigation to look into cases linked to that site yet. In Udon Thani, eight relatives of missing persons yesterday submitted their DNA samples via buccal swabs or swabs from the inside of their cheeks. They included Rayong resident Saisamorn Chidcheua whose younger brother Natthaporn has been missing in Udon Thani since 2002 and local woman Saowalak Khachamit whose older brother was abducted by three men claiming to be police in December 2008.

Meanwhile, Udon Thani police chief Pol Maj-General Peerapong Wongsaman said that so far, police had sent DNA samples of 14 relatives to the Institute of Forensic Medicine on Tuesday. As for the recent transfer of three local police officers pending disciplinary probe, Peerapong said the order had been issued in a bid to ease witnesses' worries so they could cooperate with investigators, and to prevent the tampering with evidence. The transfer order came after Dara Pasai, 60, claimed to have been kidnapped last year by four strangers, who took him to the site where the skeletons were later found, and extorted Bt260,000 from him. Some of the accused abductors were said to be policemen.

Peerapong said the transferred policemen had not yet been found guilty of any wrongdoing.

Local people and authorities in Udon Thani province's Ban Phue district joined relatives of some 30 people who went missing for years and believed slain to hold a religious ceremony at the degraded forest where human bones were found.

Eight Buddhist monks were invited to chant prayers in front of bones wrapped in white cloths in what was said was a ritual to send the spirits of these burnt victims from wandering in the forest to heaven as earlier suggested by a well-known local shaman.

The ceremony was presided over by Mr Chavayut Chantorn, the governor of Udon Thani and the chief of Udon Thani police Pol Maj Gen Peerapong Wongsamarn.

Forensic police have so far found bones from 23 tyre burning locations at the Pakudchab degraded forest reserve in Ban Phue district.

Some of these bones found were sent for laboratory test at the Royal Thai Police’s Institute of Forensic Medicine.

The test later revealed some are human bones, indicating that victims of extortions might be murdered and their bodies put on car tyres and burnt.

The investigation into the piles of human bones found in a forest in Udon Thani has taken a big step forward with the arrest of a man for the murder of a woman whose remains were found in the same area.

He is the first suspect arrested since 23 piles of burned human bones were found in a forest in Ban Phue district in Udon Thani beginning on April 21 this year.

He was captured at his home in Ban Phue district in Udon Thani and charged with murder. Police did not say when the 57-year-old man was arrested. He was taken to a media briefing at the provincial police office in Muang district on Monday.

An arrest warrant has also been obtained for former policemani in the same case, deputy police chief Pol Gen Chalermkiat Sriworakhan said.

Who was formerly stationed at Ban Phue police station, is serving life imprisonment after being convicted in another murder case.